#include<iostream>
#include<queue>

using namespace std;

class Solution {
public:
    int lastStoneWeight(vector<int>& stones) {
        priority_queue<int> heap;

        for (auto x : stones) heap.push(x);

        while (heap.size() > 1)
        {
            int a = heap.top(); heap.pop();
            int b = heap.top(); heap.pop();

            if (a > b) heap.push(a - b);
        }
        return heap.size() ? heap.top() : 0;

    }
};

int main()
{
    return 0;
}